x86-64: Move vread_tsc into a new file with sensible options

[pandora-kernel.git] / arch / x86 / kernel / tsc.c

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 24249a5..6cc6922 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -763,40 +763,6 @@ static cycle_t read_tsc(struct clocksource *cs)
                ret : clocksource_tsc.cycle_last;
 }
 
-#ifdef CONFIG_X86_64
-static cycle_t __vsyscall_fn vread_tsc(void)
-{
-       cycle_t ret;
-       u64 last;
-
-       /*
-        * Empirically, a fence (of type that depends on the CPU)
-        * before rdtsc is enough to ensure that rdtsc is ordered
-        * with respect to loads.  The various CPU manuals are unclear
-        * as to whether rdtsc can be reordered with later loads,
-        * but no one has ever seen it happen.
-        */
-       rdtsc_barrier();
-       ret = (cycle_t)vget_cycles();
-
-       last = VVAR(vsyscall_gtod_data).clock.cycle_last;
-
-       if (likely(ret >= last))
-               return ret;
-
-       /*
-        * GCC likes to generate cmov here, but this branch is extremely
-        * predictable (it's just a funciton of time and the likely is
-        * very likely) and there's a data dependence, so force GCC
-        * to generate a branch instead.  I don't barrier() because
-        * we don't actually need a barrier, and if this function
-        * ever gets inlined it will generate worse code.
-        */
-       asm volatile ("");
-       return last;
-}
-#endif
-
 static void resume_tsc(struct clocksource *cs)
 {
        clocksource_tsc.cycle_last = 0;